Conventionally, in an industrial robot system, a safety fence is typically provided to completely separate a work space of a robot and a work space of an operator from each other to prevent a situation in which the robot and the operator work in the same work space at the same time. The safety fence inhibits the operator from physically entering a movable range of the robot during an operation of the robot. In this way, safety for the operator is secured. Examples of techniques for supporting this are as follows. Patent Literature 1 discloses that a limit region which limits the operation of a robot is set in a handover region where an object is handed over between the robot and the operator when it is detected that the operator has entered the handover region. Patent Literature 2 discloses that a limit region is set with respect to coordinate values of the tip end of an arm of the robot, and a speed of the arm is limited based on a distance with this limit region.